1. Field of the Invention
The present invention relates to a battery pack provided with a memory and a secondary battery, a charging device for charging the battery pack, and an electronic device using the battery pack as a power supply.
2. Description of the Related Art
Conventionally, some types of battery packs for use in an electronic device are provided with a nonvolatile memory for storing a nominal charge capacity value and a remaining charge capacity value.
Further, there has been proposed a charging device for charging a battery pack of the above-mentioned type, in which the remaining charge capacity value is calculated based on a result of electric current integration and an initial remaining charge capacity value and a nominal remaining charge capacity value stored in a nonvolatile memory, and the initial remaining charge capacity value is rewritten into the calculated present remaining charge capacity value (see e.g. Japanese Patent Laid-Open Publication No. H06-310179).
Furthermore, an electronic device on which such a battery pack is mounted is configured to be capable of calculating a battery available time period from the present remaining charge capacity value and a load current.
However, the techniques typified by the above-described prior art do not consider how to cope with a case where a new battery pack becomes commercial after a charging device or an electronic device is sold. Therefore, when the number of types of battery packs increases or the characteristics of a battery pack are changed, there arises a problem that a charging device or an electronic device does not store data used for charge management or remaining capacity management of a battery pack, and it is impossible to perform an appropriate state management of the battery pack.